Traditional grid-powered electric sign and billboard lighting, the cost of the lights themselves is compounded by the cost of installation. To install an electric sign and billboard lighting, most models require specialized equipment and extended lengths of wiring, some of which may need to be buried underground. What is more, signs and billboards that use traditional incandescent light bulbs require constant maintenance to keep them working properly. Finally, there is the cost of the electricity to keep the sign or billboard lit night after night, for years to come.